The Museum of HP Calculators
HP Forum Archive 19
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|HP42S battery failure|
Message #1 Posted by Colin McKenzie on 26 Nov 2009, 4:47 p.m.
For some time my 42S refused to operate more than a few seconds and checking with a ohmeter showed the battery terminals resistance around 38 ohms. I used the forum to find out how to open it (had to drill out the plastic pillars)and soon found the pcb mounted electro was the culprit. I think the value is around 100uF. replaced with two 68uF in parallel and it has now come to life.Also explains why the battery change over caused loss of memory.
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